1. Field of the Invention
The field of the invention relates to user input devices for use with computer systems and electronic devices, and, more particularly to keyboards providing improved feedback to end-users.
2. Background and Related Art
One form of keyboard or keypad which has gained in popularity over the years employs a flat, thin, semi-rigid membrane, typically fashioned of plastic, which covers a single switch or switch matrix. Alpha numeric words, messages, or symbols such as "on", "reset", etc. are usually printed on the upper surface area of the membrane as desired to convey information to the end-user. Upon the user depressing the membrane over this message area contacts are thereby activated of a corresponding switch lying in vertical registry under the membrane and the message corresponding to the switch.
Because of their numerous benefits, such keyboards and keypads may be found in a wide variety of products, ranging from computer keyboards and calculators to test instrumentation, and even coffee makers and microwave ovens. These benefits include the fact that the switch contents may be hermetically sealed by the membrane from deleterious environmental factors such as coffee spills, foreign objects, dirt and dust, and the like. Additionally, the membrane is easily printed upon to convey the desired information to the user relative to each switch's function. Moreover, it is highly versatile, light, thin, flexible and therefore easily portable, readily cleaned, inexpensive, and has fewer moving parts than conventional key designs which can become quite complex and mechanically unreliable.
However, such membrane keyboards and keys are not without their own unique problems, not the least of which is the fact that such membrane keys or keyboards have little or no tactile feedback to the end user. This results in part from the fact that the throw of the key is oftentimes measured in terms of tenths or hundredths of an inch. It is thus often difficult for the user to determine whether in fact a key has been successfully depressed, rendering such things as touch typing extremely difficult and necessitating audible feedback in the form of annoying key closure beeps or the like.
Accordingly, an improvement was highly desired for such keys and keyboards which could provide this missing tactile and sensory feedback to the end-user. Such an improvement was desired which would not sacrifice the aforementioned compactness and portability afforded by such keys and keypads.
Still further, an improvement was desired which would permit the easy adjustment to match user preference or requirements in a given application of the amount of key resistance and distance of key travel which might be required.
In an effort to address this problem, some membrane keyboards were provided with domed membranes providing a small amount of additional key throw and feel. However users generally did not find this innovation to be particularly effective in terms of the touch, nor did it afford the end-user an opportunity to make any customized adjustments to the fed and touch of the keyboard.
Yet another problem associated with modern keys, keyboards, and keypads is that even when some form of tactile feedback is provided, it is generally discrete in the sense that it does not vary in terms of the qualitative or quantitative degree of feedback afforded to the end-user. For example, in a conventional computer keyboard, the user may feel a distinct click as a key is depressed. However, that is the only feedback provided to the end-user--a feedback which is singular in its type and magnitude, and with no latitude for the user being able to vary the type or magnitude of such feedback. This is not to diminish the importance of this more typical type of user feedback in keyboard art. Actually, manufacturers have taken great pains to design into computer keyboards for example, a highly distinctive click or feel. This is so important that computer manufacturers have actually built into computers sound generators which provide an audible artificial clicking sound upon depression of keys so as to create the illusion for an end-user that he or she is typing on a particular high quality keyboard with a virtual feel, as a result of this sound, different from the actual physical characteristics of the keyboard being employed. This psycho-acoustic affect has been employed with marginal results even in membrane keyboards for example wherein they are typically more devoid of any distinctive feel than are conventional keyboards.
Nevertheless, notwithstanding these attempts to improve keyboards, as aforementioned a need nevertheless existed to improve the tactile and sensory feedback to the end-user of such keys, keypads, and keyboards. Yet an additional weakness in conventional keyboard technology in affording user feedback was that such feedback was typically limited only to relatively small keys roughly the size of the human fingertip. This thereby significantly limited the ability to provide a distributed and more rich feedback over a wider area as afforded by the instant invention.